The present invention generally relates to a switch and more particularly, to a card key switch in which a card such as a driving license card, etc. or a card casing for accommodating the card therein is used as a key for actuating the card key switch.
Conventionally, there have been employed key switches provided with a locking function in order to prevent persons other than fully authorized persons having specific keys from effecting operational control of motor vehicles, apparatuses, electrical circuits, etc.
For example, there has been proposed a key switch K of this kind including a rotor 1, pin tumblers 2, a lock casing 3, a key 4, switches 5 disposed laterally of the lock casing 3, one for each of the pin tumblers 2, a main switch 6, and pin holes 7 formed in a radial direction of the lock casing 3, for receiving the pin tumblers 2 therein, respectively as shown in FIG. 1. In the key switch K, it is so arranged that the rotor 1 is locked with respect to the lock casing 3 by the pin tumblers 2 movable in the radial direction of the lock casing 3 and the pin tumblers 2 are displaced to an unlocked position of the rotor 1 upon insertion of the key 4 into the rotor 1. The main switch 6 is adapted to be opened or closed when the rotor 1 is rotated by the use of the key 4. Furthermore, in the key switch K, it is so arranged that the switches 5 are opened or closed by the respective pin tumblers 2 which have been displaced, in the pin holes 7 confronting the respective switches 5, to the unlocked position of the rotor 1 upon insertion of the key 4 into the rotor 1.
However, the known key switches of the above described type generally have such inconveniences that, since the key 4 is relatively small in size, it is not so easy to keep it when not in use and further, the key 4 is likely to be readily lost.
Another prior art can be seen in the U.S. Pat. No. 3,764,859.
In this prior art, each pin tumbler set 18' is provided with an emitter 60' and a photo detector 62' Therefore, there is an inconvenience that in a plurality of emitters and photo detectors are necessary.